Alexis Jacquier

Measurement of trabeculated left ventricular mass using cardiac magnetic resonance imaging in the diagnosis of left ventricular non-compaction

AIMS To describe a method for measuring trabeculated left ventricular (LV) mass using cardiac magnetic resonance imaging and to assess its value in the diagnosis of left ventricular non-compaction (LVNC). METHODS AND RESULTS Between January 2003 and 2008, we prospectively included 16 patients with LVNC. During the mean period, we included 16 patients with dilated cardiomyopathy (DCM), 16 patients with hypertrophic cardiomyopathy (HCM), and 16 control subjects. Left ventricular volumes, LV ejection fraction, and trabeculated LV mass were measured in the four different populations. The percentage of trabeculated LV mass was almost three times higher in the patients with LVNC (32 +/- 10%), compared with those with DCM (11 +/- 4%, P < 0.0001), HCM (12 +/- 4%, P < 0.0001), and controls (12 +/- 5%, P < 0.0001). A value of trabeculated LV mass above 20% of the global mass of the LV predicted the diagnosis of LVNC with a sensitivity of 93.7% [95% confidence interval (CI), 71.6-98.8%] and a specificity of 93.7% (95% CI, 83.1-97.8%; kappa = 0.84). CONCLUSION The method described is reproducible and provides an assessment of the global amount of LV trabeculation. A trabeculated LV mass above 20% of the global LV mass is highly sensitive and specific for the diagnosis of LVNC.

Effects of bariatric surgery on cardiac ectopic fat: lesser decrease in epicardial fat compared to visceral fat loss and no change in myocardial triglyceride content.

OBJECTIVES This study investigated the effect of bariatric surgery (BS)-induced weight loss on cardiac ectopic fat using 3T magnetic resonance imaging in morbid obesity. BACKGROUND Heart disease is one of the leading causes of mortality and morbidity in obese patients. Deposition of cardiac ectopic fat has been related to increased heart risk. Whether sustained weight loss can modulate epicardial fat or myocardial fat is unknown. METHODS Twenty-three morbidly obese patients underwent 1H-magnetic resonance spectroscopy to determine myocardial triglyceride content (MTGC), magnetic resonance imaging to assess epicardial fat volume (EFV), cardiac function, and computed tomography visceral abdominal fat (VAF) measurements at baseline and 6 months after BS. RESULTS The BS reduced body mass index significantly, from 43.1±4.5 kg/m2 to 32.3±4.0 kg/m2, subcutaneous fat from 649±162 cm2 to 442±127 cm2, VAF from 190±83 cm2 to 107±44 cm2, and EFV from 137±37 ml to 98±25 ml (all p<0.0001). There was no significant change in MTGC: 1.03±0.2% versus 1.1±0.2% (p=0.85). A significant reduction in left ventricular mass (118±24 g vs. 101±18 g) and cardiac output (7.1±1.6 l/min vs. 5.4±1.0 l/min) was observed and was statistically associated with weight loss (p<0.05). The loss in EFV was limited (-27±11%) compared to VAF diminution (-40±19%). The EFV variation was not correlated with percentage of body mass index or VAF loss (p=0.007). The ratio of %EFV to %VAF loss decreased with sleep apnea syndrome (1.34±0.3 vs. 0.52±0.08, p<0.05). CONCLUSIONS Six-month BS modulates differently cardiac ectopic fat deposition, with a significant decrease in epicardial fat and no change in myocardial fat. Epicardial fat volume loss was limited in patients with sleep apnea. (Impact of Bariatric Surgery on Epicardial Adipose Tissue and on Myocardial Function; NCT01284816).

Uterus and bladder necrosis after uterine artery embolisation for postpartum haemorrhage

Case reportA 32 year old primipara was admitted for prematurerupture of the membranes at 37 weeks of gestation. Shehad a history of miscarriage with curettage in associa-tion with previous pregnancy. She delivered a healthymale child. After manual delivery of the placenta, ex-ploration of the uterus and oxytocin was required tocontrol bleeding. Selective uterine artery embolisationwas carried out because there was an adherent placentalcotyledon in the left uterine horn causing uncontrollablebleeding.Selective catheterisation of the left internal iliac arteryand superselective catheterisation of the left uterine arterieswere performed using a 5F cobra-shaped catheter (Cobra;Terumo, Tokyo, Japan) and a 0.035-in. diameter hydro-philicpolymer-coatedguidewire(Radifocus;Terumo)fromthe contralateral groin. The angiography showed no anasto-mosis between the uterine and the ovarian artery anddemonstrated an arterial tear with massive extravasationof contrast material in the uterine cavity. Bilateral free-flowembolisation was performed under fluoroscopic controlusing iodinated contrast media mixed with gelatine spongepledgets (Curaspon; Curaspon Healthcare, Netherlands)particles obtained by scraping a piece of gelfoam with asurgical blade. No vascular spasm was observed.On day 21, the patient was readmitted for pelvic pain andabnormal bleeding.Vaginal examination revealed thathalf ofthe uterine cervix presented an abnormal colour suggestiveof ischaemia. Pelvic magnetic resonance imaging revealeda bulky uterus with a small peripheral enhancement rim.The central portion of the organ was completely necrotic.Subtotal hysterectomy was performed. Both uterineartery pedicles were filled with thrombus. Surgical explo-ration also revealed a 5-cm necrotic area on the bladderwall (Fig. 1). Cystoscopic examination demonstrated mu-cosal deterioration and the necrotic portion was excised.Cystography on day 13 was normal. Two months aftersurgery, the cervix and the vagina were normal.Histological examination of the surgical specimensshowed massive ischaemic necrosis of the whole uterusexcept the deep myometrium. Plurinuclear and giant cellsoccupying the vessels in the lower part of the uterus hadphagocytosed small foreign bodies. Some vessels containedunusual weakly coloured star-shaped structures probablycorresponding to the gelatine sponge particles used forembolisation. Vessels containing those structures were lessdilated, smaller in diameter and thicker-walled than othervessels. Examination of bladder tissue demonstrated com-plete disappearance of the mucosa together with ischaemicchanges throughout the wall.DiscussionPostpartum haemorrhage is the leading cause of maternalmortality throughout the world.

Assessment of epicardial fat volume and myocardial triglyceride content in severely obese subjects: relationship to metabolic profile, cardiac function and visceral fat

Objective:To assess epicardial fat volume (EFV), myocardial TG content (MTGC) and metabolic profile in severely obese patients, and to determine whether ectopic fat depots are linked to metabolic disorders or myocardial function.Research design and methods:Sixty-three subjects with normal LV function and no coronary artery disease, including 33 lean (BMI: 21.4±2.0 kg m−2) and 30 obese (BMI: 41.8±6 kg m−2) patients, underwent 3-T cardiovascular MRI, and anthropometric, biological and visceral abdominal fat (VAT) assessments. EFV was measured by short-axis slice imaging and myocardial (intra-myocellular) TG content was measured by proton magnetic resonance spectroscopy.Results:EFV and MTGC were positively correlated (r=0.52, P<0.0001), and were both strongly correlated with age, BMI, waist circumference and VAT, but not with severity of obesity. EFV and MTGC were significantly higher in obese patients than in lean controls (141±18 versus 79±7 ml, P=0.0001; 1.0±0.1 versus 0.6±0.1%, P=0.01, respectively), but some differences were found between the two cardiac depots: EFV was higher in diabetic obese subjects as compared with that in non-diabetic obese subjects (213±34 versus 141±18 ml, P=0.03), and was correlated with parameters of glucose tolerance (fasting plasma glucose, insulin and HOMA-IR), whereas MTGC was not. EFV and MTGC were both associated with parameters of lipid profile or inflammation (TGs, CRP). Remarkably, this was VAT-dependent, as only VAT remained independently associated with metabolic parameters (P<0.01). Concerning myocardial function, MTGC was the only parameter independently associated with stroke volume (β=−0.38, P=0.01), suggesting an impact of cardiac steatosis in cardiac function.Conclusions:These data show that VAT dominates the relationship between EFV, MTGC and metabolic measures, and uncover specific partitioning of cardiac ectopic lipid deposition.

Assessment of left ventricular non-compaction in adults: side-by-side comparison of cardiac magnetic resonance imaging with echocardiography.

BACKGROUND Two-dimensional echocardiography images obtained at end-diastole and end-systole and cardiac magnetic resonance (CMR) images obtained at end-diastole represent the three imaging methodologies validated for diagnosis of left ventricular non-compaction (LVNC). No study has compared these methodologies in assessing the magnitude of non-compaction. AIMS To compare two-dimensional echocardiography with CMR in the evaluation of patients with suspected LVNC. METHODS Sixteen patients (48+/-17 years) with LVNC underwent echocardiography and CMR within the same week. Echocardiography images obtained at end-diastole and end-systole were compared in a blinded fashion with those obtained by CMR at end-diastole to assess non-compaction in 17 anatomical segments. RESULTS All segments could be analysed by CMR, whereas only 238 (87.5%) and 237 (87.1%) could be analysed by echocardiography at end-diastole and end-systole, respectively (p=0.002). Among the analysable segments, a two-layered structure was observed in 54.0% by CMR, 42.9% by echocardiography at end-diastole and 41.4% by echocardiography at end-systole (p=0.006). Similar distribution patterns were observed with the two echocardiographic methodologies. However, compared with echocardiography, CMR identified a higher rate of two-layered structures in the anterior, anterolateral, inferolateral and inferior segments. Echocardiography at end-systole underestimated the NC/C maximum ratio compared with CMR (p=0.04) and echocardiography at end-diastole (p=0.003). No significant difference was observed between CMR and echocardiography at end-diastole (p=0.83). Interobserver reproducibility of the NC/C maximum ratio was similar for the three methodologies. CONCLUSION CMR appears superior to standard echocardiography in assessing the extent of non-compaction and provides supplemental morphological information beyond that obtained with conventional echocardiography.

Imaging investigations in infective endocarditis: Current approach and perspectives

Infective endocarditis is a serious disease that needs rapid diagnosis and accurate risk stratification to offer the best therapeutic strategy. Echocardiography plays a key role in the management of the disease but may be limited in some clinical situations. Moreover, this method is insensitive for very early detection of the infection and assessment of therapeutic response because it does not provide imaging at the molecular and cellular levels. Recently, several novel morphological, molecular and hybrid imaging modalities have been investigated in infective endocarditis and offer new perspectives for better management of the disease.

Multidetector Computed Tomography in Reperfused Acute Myocardial Infarction: Assessment of Infarct Size and No-reflow in Comparison With Cardiac Magnetic Resonance Imaging

Objectives:(1) To determine the accuracy of delayed enhancement multidetector computed tomography (MDCT) in measuring the extent of acute myocardial infarct and no-reflow areas using cardiac magnetic resonance imaging (MRI) as standard of reference and (2) to define the optimum timing between injection and MDCT image acquisition to characterize infarcted myocardium and no-reflow areas after reperfusion therapy. Materials and Methods:Nineteen patients were prospectively included after acute myocardial infarction and revascularization. Each patient had an MDCT acquisition before and 5 and 10 minutes after injection of 1.5 mL/kg iodinated contrast medium, and a contrast-enhanced MRI at 5 and 10 minutes after injection of 0.2 mmol/kg gadolinium chelate. We assessed image quality and infarct extent using MDCT and MRI, and we measured parameters related to iodinated contrast media kinetics (&Dgr;HU and &Dgr;HU ratio). Results:The areas of hyperenhanced myocardium located on the MDCT corresponded to the occluded vessel located on the coronary angiogram (&kgr; = 0.9). There were strong correlations between the extent of hyperenhanced infarcted myocardium on MDCT and MRI at 5 minutes (20.4% ± 2.7% of left ventricle (LV) and 20.9% ± 2.4%, respectively, R = 0.85; P < 0.0001) and 10 minutes after injection (21.0% ± 2.9% of LV and 19.4% ± 2.5%, respectively, R = 0.80; P < 0.0001). However, the correlation between the area of hypoenhanced myocardium measured using MDCT and CMR 5 minutes after injection (R = 0.86; P < 0.0001) was better than the measurement obtained 10 minutes after injection (R = 0.64; P = 0.002). On contrast-enhanced MDCT, 5 minutes after injection, the signal-to-noise ratio was significantly higher than at 10 minutes after injection in LV blood (28 ± 1 to 21 ± 1, respectively; P = 0.0007), normal myocardium (18 ± 1 to 15 ± 1; P = 0.0009), and hyperenhanced infarcted myocardium (24 ± 1 to 20 ± 1; P = 0.004). MDCT image quality was significantly better at 5 minutes (3.2 ± 0.1) than at 10 minutes (2.8 ± 0.2, P = 0.01, &kgr; = 0.4). The &Dgr;HU ratio increased slightly but significantly between 5 minutes (0.83 ± 0.01) and 10 minutes (0.93 ± 0.01; P = 0.01), suggesting a slow wash-in and wash-out of contrast medium in infarcted myocardium. Conclusion:In ST segment elevation myocardial infarction patients contrast-enhanced MDCT is an accurate method for characterizing and sizing myocardial infarct and no-reflow. Contrast-enhanced MDCT performed 5 minutes after injection yields a higher signal-to-noise ratio and image quality than the 10 minutes time point with no difference in the extent of infarct measurement.

Ectopic fat storage in the pancreas using 1H-MRS: importance of diabetic status and modulation with bariatric surgery-induced weight loss.

Objectives:Recent literature suggests that ectopic fat deposition in the pancreas may contribute to endocrine and exocrine organ dysfunction, such as type 2 diabetes (T2D), pancreatitis or pancreatic cancer. The aim of this study was to determine factors associated with pancreatic triglyceride content (PTGC), and to investigate the impact of bariatric surgery on ectopic fat pads, pancreatic fat (PTGC) and hepatic fat (HTGC).Subjects:In all, 45 subjects (13 lean, 13 obese nondiabetics and 19 T2D, matched for age and gender) underwent 1H-magnetic resonance spectroscopy, computed tomography of the visceral abdominal fat, metabolic and lipidomic analysis, including insulin-resistance homeostasis model assessment (HOMA-IR), insulin-secretion homeostasis model assessment (HOMA-B) and plasma fatty-acid composition. Twenty obese subjects were reassessed 6 months after the bariatric surgery.Results:PTGC was significantly higher in type 2 diabetic subjects (23.8±3.2%) compared with obese (14.0±3.3; P=0.03) and lean subjects (7.5±0.9%; P=0.0002). PTGC remained significantly associated with T2D after adjusting for age and sex (β=0.47; P=0.004) or even after adjusting for waist circumference, triglycerides and HOMA-IR (β=0.32; P=0.04). T2D, C18:1n-9 (oleic acid), uric acid, triglycerides and plasminogen activator inhibitor-1 were the five more important parameters involved in PTGC prediction (explained 80% of PTGC variance). Bariatric surgery induced a huge reduction of both HTGC (−51.2±7.9%) and PTGC (−43.8±7.0%) reaching lean levels, whereas body mass index remained greatly elevated. An improvement of insulin resistance HOMA-IR and no change in HOMA-B were observed after bariatric surgery. The PTGC or HTGC losses were not correlated, suggesting tissue-specific mobilization of these ectopic fat stores.Conclusion:Pancreatic fat increased with T2D and drastically decreased after the bariatric surgery. This suggests that decreased PTGC may contribute to improved beta cell function seen after the bariatric surgery. Further, long-term interventional studies are warranted to examine this hypothesis and to determine the degree to which ectopic fat mobilization may mediate the improvement in endocrine and exocrine pancreatic functions.

Ethylene vinyl alcohol copolymer (Onyx®) in peripheral interventional radiology: indications, advantages and limitations.

Onyx(®) is a remarkable liquid embolizing agent that may allow a well-trained operator to undertake challenging embolization procedures. In multiple interventional radiology indications, the physico-chemical properties of Onyx(®) allow safe embolization. The purpose of this article is to review the advantages and disadvantages of Onyx(®) and identify its main indications.

Value of in vivo T2 measurement for myocardial fibrosis assessment in diabetic mice at 11.75 T.

Objective:The aim of the study was to assess the value of in vivo T2 measurements to noninvasively quantify myocardial fibrosis in diabetic mice at 11.75 T. Diabetic cardiomyopathy is characterized by extracellular matrix alteration and microcirculation impairment. These conditions might provide electrical heterogeneity, which is a substrate for arrhythmogenesis. T1 mapping has been proposed to quantify diffuse myocardial fibrosis in cardiac diseases but has several limitations. T2 measurement may represent an alternative for fibrosis quantification at high magnetic field. Materials and Methods:A magnetic resonance imaging protocol including in vivo T2 measurements at 11.75 T was performed in 9 male C57BL/6J mice after 8 weeks of streptozotocin-induced diabetes and in 9 control mice. Programmed ventricular stimulation was performed in both groups. T2 measurements were compared with histologic quantification of fibrosis using picrosirius red staining. Results:Myocardial T2 was significantly lower in diabetic mice (13.8 ± 2.8 ms) than in controls (18.9 ± 2.3 ms, P < 0.001). There was a good correlation between T2 and fibrosis area obtained by histopathology (R2 = 0.947, P < 0.001). During programmed ventricular stimulation, 3 nonsustained ventricular tachycardias were induced in diabetic mice versus none in the control group. Conclusions:The in vivo T2 relaxation time strongly correlated with myocardial fibrosis area assessed with histologic staining in diabetic mice.